The structure and devitrification of CaO-Al2O3-SiO2 glasses contg. SiO2 14.3-76.9, Al2O3 9.0-43.0, and CaO 10.0-50.0 mol% were studied by DTA and x-ray diffraction. The glasses were synthesized from SiO2, Al2O3, and CaCO3 powders at ∼1500°. The crystallizability of glasses increased and their transition and softening temps. decreased with increasing CaO/(Al2O3 + SiO2) ratio. The continuous network of the glasses with Al2O3/CaO ratio >1 was partially modified by Al3+ ions in >4 coordination. The modifying effect of Ca2+ ions was established. Anorthite [1302-54-1] crystd. in glasses with low CaO content and gehlenite [1302-56-3] in glasses with high CaO content.
Structure and devitrification behaviour of CaO-Al2O3-SiO2 glasses / A., Buri; Branda, Francesco; D., Caferra; A., Marotta. - In: SILICATES INDUSTRIELS. - ISSN 0037-5225. - STAMPA. - 46:(1981), pp. 59-61.
Structure and devitrification behaviour of CaO-Al2O3-SiO2 glasses
BRANDA, FRANCESCO;
1981
Abstract
The structure and devitrification of CaO-Al2O3-SiO2 glasses contg. SiO2 14.3-76.9, Al2O3 9.0-43.0, and CaO 10.0-50.0 mol% were studied by DTA and x-ray diffraction. The glasses were synthesized from SiO2, Al2O3, and CaCO3 powders at ∼1500°. The crystallizability of glasses increased and their transition and softening temps. decreased with increasing CaO/(Al2O3 + SiO2) ratio. The continuous network of the glasses with Al2O3/CaO ratio >1 was partially modified by Al3+ ions in >4 coordination. The modifying effect of Ca2+ ions was established. Anorthite [1302-54-1] crystd. in glasses with low CaO content and gehlenite [1302-56-3] in glasses with high CaO content.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
